k8s-kubelet.md

k8s-kubelet

DEPRECATED Discovers service endpoints running on the same node as the agent by querying the local kubelet instance. It is generally recommended to use the k8s-api observer because authentication to the local kubelet can be more difficult to setup, and also the kubelet API is technically not documented for public consumption, so this observer may break more easily in future K8s versions.

Observer Type: k8s-kubelet

Observer Source Code

Configuration

Config option	Required	Type	Description
pollIntervalSeconds	no	integer	How often to poll the Kubelet instance for pod information (default: 10)
kubeletAPI	no	object (see below)	Config for the Kubelet HTTP client

The nested kubeletAPI config object has the following fields:

Config option	Required	Type	Description
url	no	string	URL of the Kubelet instance. This will default to http://<current node hostname>:10255 if not provided.
authType	no	string	Can be none for no auth, tls for TLS client cert auth, or serviceAccount to use the pod's default service account token to authenticate. (default: none)
skipVerify	no	bool	Whether to skip verification of the Kubelet's TLS cert (default: true)
caCertPath	no	string	Path to the CA cert that has signed the Kubelet's TLS cert, unnecessary if skipVerify is set to false.
clientCertPath	no	string	Path to the client TLS cert to use if authType is set to tls
clientKeyPath	no	string	Path to the client TLS key to use if authType is set to tls
logResponses	no	bool	Whether to log the raw cadvisor response at the debug level for debugging purposes. (default: false)

Target Variables

The following fields are available on targets generated by this observer and can be used in discovery rules.

Name	Type	Description
container_name	string	The first and primary name of the container as it is known to the container runtime (e.g. Docker).
has_port	string	Set to true if the endpoint has a port assigned to it. This will be false for endpoints that represent a host/container as a whole.
ip_address	string	The IP address of the endpoint if the host is in the from of an IPv4 address
network_port	string	An alias for port
private_port	string	The port that the service endpoint runs on inside the container
public_port	string	The port exposed outside the container
alternate_port	integer	Used for services that are accessed through some kind of NAT redirection as Docker does. This could be either the public port or the private one.
container_command	string	The command used when running the container exposing the endpoint
container_id	string	The ID of the container exposing the endpoint
container_image	string	The image name of the container exposing the endpoint
container_labels	map of string	A map that contains container label key/value pairs. You can use the Contains and Get helper functions in discovery rules to make use of this. See Endpoint Discovery. For containers managed by Kubernetes, this will be set to the pod's labels, as individual containers do not have labels in Kubernetes proper.
container_names	list of string	A list of container names of the container exposing the endpoint
container_state	string	The container state, will usually be "running" since otherwise the container wouldn't have a port exposed to be discovered.
discovered_by	string	The observer that discovered this endpoint
host	string	The hostname/IP address of the endpoint. If this is an IPv6 address, it will be surrounded by [ and ].
id	string
name	string	A observer assigned name of the endpoint. For example, if using the k8s-api observer, name will be the port name in the pod spec, if any.
orchestrator	integer
port	integer	The TCP/UDP port number of the endpoint
port_labels	map of string	A map of labels on the container port
port_type	string	TCP or UDP
target	string	The type of the thing that this endpoint directly refers to. If the endpoint has a host and port associated with it (most common), the value will be hostport. Other possible values are: pod, container, host. See the docs for the specific observer you are using for more details on what types that observer emits.

Dimensions

These dimensions are added to all metrics that are emitted for this discovery target. These variables are also available to use as variables in discovery rules.

Name	Description
container_id	The container id of the container running this endpoint.
container_image	The image name (including tags) of the running container
container_name	The primary name of the running container -- Docker containers can have multiple names but this will be the first name, if any.
container_spec_name	The short name of the container in the pod spec, NOT the running container's name in the Docker engine
kubernetes_namespace	The namespace that the discovered service endpoint is running in.
kubernetes_pod_name	The name of the running pod that is exposing the discovered endpoint
kubernetes_pod_uid	The UID of the pod that is exposing the discovered endpoint